In methods known as conventional color photography, a photographic camera material (a so-called color negative film) in general comprises a blue light-recording, yellow dye-forming layer, a green light-recording, magenta dye-forming layer, and a red light-recording, cyan dye-forming layer. Accordingly, the function of conventional color negative films is defined as conversion of lightness (or darkness) information for each color component of a photographic object to yellow, magenta or cyan image density information, followed by transfer of the information, via a printing process, to a blue-sensitive layer, green-sensitive layer or a red-sensitive layer of photographic color paper. A performance element of this color film for camera use is represented by sensitivity and image quality, and the image quality element is further classified into graininess, sharpness and color reproduction. To enhance photographic performance of the color film for camera use, the design is made to be such that the spectral sensitivity distribution is adjusted to achieve desired color reproduction and a compound capable of releasing a development inhibitor upon development (a so-called DIR compound) is incorporated to enhance an interlayer development inhibiting effect (so-called interimage effect), while enhancing sensitivity, graininess and sharpness respectively in each layer. However, there is a trade-off relationship such that when sensitivity is enhanced, image tends to deteriorate. It is therefore not too much to say that the history of development or improvements in color film for camera use is to be that of compatibility of sensitivity and image quality with each other.
There is also known a method in which images formed in a color negative film are read by an optical means such as a scanner, converted to electric signals and then subjected to image processing to prepare digital image data, and based thereon, image information is transferred onto another image recording material. In this case, finished prints can be obtained using a digital printer in which a finished print is obtained by subjecting color paper to scanning exposure, or using non-silver printers such as an ink-jet printer, a sublimation-type thermal transfer printer and an electrophotographic printer. Further, when assuming that information recorded on color negative film is not to be directly projected through an optical system onto color paper to prepare a finished print, a condition in which blue information, green information and red information of a photographic object respectively correspond to yellow, magenta and cyan image information, is not necessarily required in film design. Accordingly, there is still room for enhancements of performance by designing constitutions different from those of conventional photographic materials.
As a photosensitive element for converting images to digitized image data on the premise of no optical printing being required is known a method in which a fluorescent material is contained in an interlayer without incorporating different dye-forming couplers respectively into blue-sensitive, green-sensitive and red-sensitive layers and blue-green- and red-separated images are extracted by scanning, in both a reflection and a transmission means, developed images in different photosensitive layers, which have the same hue and further subjecting the image data to image processing, as disclosed in U.S. Pat. Nos. 5,418,119 and 5,420,003. This method is advantageous in terms of simplification of photosensitive materials and processing thereof, and rapid access but can not unfortunately be employed as a means for enhancing the image quality of conventional color photographic materials.
JP-A 61-34541 (hereinafter, the term, JP-A means an unexamined and published Japanese Patent Application) describes a method of providing a so-called donor layer giving an inhibiting effect to the red-sensitive layer as a means for bringing a gravity center wavelength of an interimage effect distribution in the green region of the red-sensitive layer close to the gravity center wavelength in spectral sensitivity of the green-sensitive layer. This method is effective to achieve faithful color reproduction. However, color formation of developed film, which is basically integrated to yellow, magenta and cyan information provides no specific information when reading the film by a scanner. Therefore, it is not assured that the method described above is a positive means for obtaining color digitized images of high sensitivity as well as high image quality.
JP-A 11-72870 discloses a means for providing a non-visible light-sensitive layer to enhance color reproduction. In this case, however, color formation of a developed film is basically integrated into yellow, magenta and cyan information, providing no specific information when the film is read by a scanner. JP-A 11-143031 discloses a means for enhancing color reproduction in which information in the non-visible light-sensitive layer is extracted as separate information at the time of scanning the developed film and combined with RGB signals. This method was intended to solve partially unwanted color reproduction by providing the non-visible light-sensitive layer but was not a sufficient technical means for solving the trade-off relationship between sensitivity and color reproduction.